Influence of Laser Surface Texturing Distribution Patterns on the Hydrodynamic Lubrication

2010 ◽  
Vol 97-101 ◽  
pp. 1429-1432 ◽  
Author(s):  
Hong Bin Liu ◽  
Hong Biao Han ◽  
Yu Jun Xue ◽  
Ji Shun Li
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Texturing ◽  
Distribution Patterns ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Laser Texturing ◽  
Coverage Ratio ◽  
Lubricating Film ◽  
Load Carrying ◽  
Film Lubrication

Laser Surface Texturing (LST) is an advanced method of surface micro-texturing technology. The aim of this paper is to investigate the influence of laser surface texturing distribution patterns on lubricant characteristics for laser texturing surfaces against cylindrical under conditions of film lubrication. The laser texturing surfaces are processed with power levels under YAG laser. Under conditions of constant depth and area coverage ratio of LST,patterns of the texture distribution and the sliding orientation relative to the texture were systematically varied. The experimental results suggested that 20° circumferential interval can increase the load-carrying ability of lubricating film.

Effectiveness of multi-shape laser surface texturing in the reduction of friction under lubrication regime

2016 ◽  
Vol 68 (1) ◽  
pp. 116-124 ◽  
Author(s):  
Dawit Zenebe Segu ◽  
Pyung Hwang
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Textured Surface ◽  
Content Type ◽  
Laser Ablation Process ◽  
Specific Formula ◽  
Steel Surfaces ◽  
Lubrication Conditions

Purpose – The purpose of this paper is to investigate and discuss the effect of multi-shape laser surface texturing (LST) steel surfaces on tribological performance. Design/methodology/approach – The textured surface with some specific formula arrays was fabricated by laser ablation process by combining patterns of circles and triangles, circles and squares and circles and ellipses. The tribological test was performed by a flat-on-flat tribometer under dry and lubrication conditions, and results were compared with that of untextured surface. Findings – The results showed that the textured surface had better friction coefficient performance than the untextured surface due to hydrodynamic lubrication effect. Through an increase in sliding speed, the beneficial effect of LST performance was achieved under dry and lubrication conditions. Originality/value – This paper develops multi-shape LST steel surfaces for improving the friction and wear performance under dry and lubrication conditions.

scholarly journals Influence of Laser Surface Texturing Sequence on Fatigue Properties of Coated Cold Work Tool Steel

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1636
Author(s):  
Marko Sedlaček ◽  
Agnieszka Zuzanna Guštin ◽  
Borut Žužek
Keyword(s):  
Fatigue Life ◽  
Tool Steel ◽  
Cold Work ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Fatigue Properties ◽  
Laser Texturing ◽  
Coating Deposition ◽  
Cold Work Tool Steel

The aim of this research was to investigate the influence of laser surface texturing sequence on the fatigue properties of cold-work tool steel. For this reason, polished hourglass-type test specimens made from cold-work tool steel (K890) were surface textured using laser texturing. Surface textures were introduced before and after hard coating deposition (TiAlN) with the aim to investigate the sequence of surface-texturing process. It was found that coating deposition prolongs the fatigue life. The fatigue life behaviour can be influenced also by the sequence of surface texturing. In the case when laser texturing is done after coating deposition, it suffers in fatigue life properties. From a lower magnification, a fractured surface looks like a quasi-ductile fracture, but a closer look reveals that there is very little plastic deformation and some small flat regions can be seen with clear evidence of a brittle fracture mechanism with cleavage. Due to low fracture toughness of investigated steel, no fatigue striations of crack growth steps were found on the fractured surfaces.

scholarly journals Polydopamine-Assisted Immobilization of Chitosan Brushes on a Textured CoCrMo Alloy to Improve its Tribology and Biocompatibility

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3014 ◽  
Author(s):  
Liguo Qin ◽  
Hongjiang Sun ◽  
Mahshid Hafezi ◽  
Yali Zhang
Keyword(s):  
Tribological Properties ◽  
Photoelectron Spectroscopy ◽  
Polymer Brushes ◽  
Hydrodynamic Lubrication ◽  
Synergistic Effects ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Textured Surface ◽  
Osteoblast Cells

Due to their bioinert and reliable tribological performance, cobalt chromium molybdenum (CoCrMo) alloys have been widely used for articular joint implant applications. However, friction and wear issues are still the main reasons for the failure of implants. As a result, the improvement of the tribological properties and biocompatibility of these alloys is still needed. Thus, surface modification is of great interest for implant manufacturers and for clinical applications. In this study, a strategy combining laser surface texturing and chitosan grafting (mussel inspired) was used to improve the tribological and biocompatible behaviors of CoCrMo. The microstructure and chemical composition were investigated by atomic force microscopy, scanning electron microscopy, and X-ray photoelectron spectroscopy, respectively. The tribological properties were discussed to determine their synergistic effects. To evaluate their biocompatibility, osteoblast cells were cocultured with the modified surface. The results show that there is a distinct synergistic effect between laser surface texturing and polymer brushes for improving tribological behaviors and biocompatibility. The prepared chitosan brushes on a textured surface are a strong mechanism for reducing friction force. The dimples took part in the hydrodynamic lubrication and acted as the container for replenishing the consumed lubricants. These brushes also promote the formation of a local lubricating film. The wear resistance of the chitosan brushes was immensely improved. Further, the worn process was observed, and the mechanism of destruction was demonstrated. Co-culturing with osteoblast cells showed that the texture and grafting have potential applications in enhancing the differentiation and orientation of osteoblast cells.

Hydrodynamic Lubrication and Load Carrying Capacity Analysis of Laser Surface Texturing Valve Core

2016 ◽  
Vol 693 ◽  
pp. 348-355
Author(s):  
Tao He ◽  
Chuan Li Wang ◽  
Hai Shun Deng ◽  
Yan Long Huang ◽  
Cao Feng Yu
Keyword(s):  
Surface Pressure ◽  
Carrying Capacity ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Surface Texturing ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Process Technology ◽  
The Core ◽  
Lubrication Performance

Take water hydraulic slide valve core as the research object. Laser surface texturing (LST) technology was used to improve the valve core carrying capacity and hydrodynamic lubrication characteristics, which can process micro-texture on the surface of the core. And CFD method was taken to calculate flow field of smooth and laser surface texturing core respectively. For studying the influence of valve core micro-texture and valve core overlap lengths on hydrodynamic lubrication characteristic and carrying capacity of the core, core surface pressure distribution, surface pressure and friction force curves were drawn. Results show: The smooth valve core does not produce hydrodynamic lubrication effect, but textured valve core can bring the oil film load capacity, so as to make the effect of mixed friction between valve core and sleeve weaken. And along with the decrease of the core overlap length, the carrying capacity on the surface of the textured valve core does not decrease but increase when the valve core overlap length amount is greater than 2.5mm.The results provide important theoretical reference of studying and applying LST process technology to the valve core friction pair’s lubrication performance.

scholarly journals Effects of Laser Texture Oxidation and High-Temperature Annealing of TiV Alloy Thin Films on Mechanical and Antibacterial Properties and Cytotoxicity

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2495 ◽  
Author(s):  
Yin-Yu Chang ◽  
Jia-Hao Zhang ◽  
Heng-Li Huang
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Surface Texturing ◽  
Antibacterial Properties ◽  
Pure Titanium ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Cell Cytotoxicity ◽  
High Temperature Annealing ◽  
Laser Texturing

Titanium dioxide and vanadium oxides have been applied extensively in industrial and medical fields. The objective of this study was to develop various composite structures of titanium and vanadium oxide (Ti-V-O) coatings on pure titanium through high-temperature annealing and laser texturing oxidation, separately; additionally, surface morphologies, tribological and hydrophilic properties, and antibacterial and biocompatibility abilities of these Ti-V-O coatings were evaluated. TiV alloy thin films were deposited on pure titanium and then annealed to form Ti-V-O coatings through thermal oxidation and laser texturing oxidation. Ball-on-disc wear tests and contact angle tests were conducted to evaluate the tribological properties and wettability of the coatings, respectively. The antibacterial activity of the coatings was estimated by SYTO9 nucleic acid staining with Staphylococcus aureus (Gram-positive bacteria). The cell cytotoxicity of the coatings was analyzed following the ISO 10995-5:2009 standard with human skin fibroblast cells. The Ti-V-O coatings, subjected to annealing at 700 °C, demonstrated higher hardness (Hv 1171) and a lower friction coefficient (0.6). The highest hardness (Hv 2711) and the lowest friction coefficient (0.52) were obtained for the Ti-V-O after laser surface texturing oxidation at 100 kHz. The oxide coating obtained from 100 kHz laser texturing oxidation exhibited the lotus effect because of its systematic textured microstructures, and displayed superhydrophobic surface properties. Compared with the unannealed TiV coating, both the samples with high-temperature annealing and laser surface texturing oxidation had excellent antibacterial properties to Staphylococcus aureus. However, the Ti-V-O thin films exhibited notable cell cytotoxicity. Although the cell viability on Ti-V-O coatings were not ideal, this study confirmed improvement in surface hardness, tribology, and antibacterial performance in Ti-V-O coatings, which may have potential for use in biomedical tools, devices, and equipment.

Tribological Properties of Laser Surface Texturing and Coating Duplex-Treated Surface

2011 ◽  
Vol 686 ◽  
pp. 706-710
Author(s):  
Jie Jiang ◽  
Dang Sheng Xiong ◽  
Jian Liang Li ◽  
Yan Shi
Keyword(s):  
High Temperature ◽  
Wear Rate ◽  
Plasma Nitriding ◽  
Surface Texturing ◽  
High Hardness ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Textured Surface ◽  
Wear Properties ◽  
Lubricating Film

Components of space machines often works at high temperature and vacuum, or on other rigour conditions, the traditional liquid lubricant cannot satisfy the requirement. The common solid lubricant is hard to supply between two friction surfaces continuously and it is easily decomposed and failure at high temperature. It is an urgent need to study a new type of lubrication technology. In this paper, the surface of 1Cr18Ni9Ti with high hardness and micro dimples was prepared through laser texturing and plasma molybdenizing/plasma nitriding duplex treatment. The textured surface was coated with MoS2 lubricating film and the friction and wear properties from room temperature to high temperature were evaluated. The results show that the laser surface textured dimples trap hard abrasive particles and reduce the damage to the lubricating film, and thus decrease the wear rate. The optimum dimple density of 7.1% is obtained. At elevated temperature, the wear rate of molybdenized texture or nitrided texture is lower than that of the matrix and single textured surface.

Partial Elastomer Texturing in Soft Elasto Hydrodynamic Lubrication

2008 ◽  
Author(s):  
Alexey Shinkarenko ◽  
Yuri Kligerman ◽  
Izhak Etsion
Keyword(s):  
Hydrodynamic Lubrication ◽  
Surface Texturing ◽  
Leading Edge ◽  
Friction Reduction ◽  
Fluid Film ◽  
Laser Surface Texturing ◽  
Pressure Fields ◽  
Load Carrying ◽  
Micro Dimples ◽  
Viscous Fluid Film

A dimensionless theoretical model of Soft Elasto Hydrodynamic Lubrication (SEHL) between partially textured elastomer and rigid counterpart is developed. The model consists of a soft elastomer with partial Laser Surface Texturing (LST) and an absolutely rigid and smooth counterpart moving relatively to each other in the presence of viscous lubricant. The elastomer surface is partially textured at its leading edge in the form of spherical micro-dimples. The pressure distribution in the fluid film and the elastic deformations of the elastomer are obtained from a simultaneous solution of the Reynolds equation and the equation of linear elasticity, respectively. Friction force and load carrying capacity are evaluated by integration of the shear stress and pressure fields in the viscous fluid film, respectively. The main goal of the present work is to study the potential of the elastomer partial LST in SEHL to friction reduction.

The Effect of Laser Surface Texturing on Soft Elasto-Hydrodynamic Lubrication Considering Non-Linear Elasticity

2008 ◽  
Author(s):  
Alexey Shinkarenko ◽  
Yuri Kligerman ◽  
Izhak Etsion
Keyword(s):  
Linear Model ◽  
Hydrodynamic Lubrication ◽  
Load Capacity ◽  
Surface Texturing ◽  
Laser Surface ◽  
Operating Conditions ◽  
Constitutive Law ◽  
Laser Surface Texturing ◽  
Wide Range ◽  
Non Linear

A non-linear theoretical model is presented to study the effect of laser surface texturing (LST) on the load carrying capacity in soft elasto-hydrodynamic lubrication (SEHL). Both geometrical and physical non-linearity of the elastomer is considered by using a logarithmic strain and the Mooney-Rivlin constitutive law, respectively. The results of the present non-linear model are compared with those of a previous linear one over a wide range of operating conditions. It is found that the two models predict the same optimum LST parameters for maximum load capacity but the non-linear model gives load capacity that is up to 10% lower than that obtained from the linear model.

scholarly journals Does laser surface texturing really have a negative impact on the fatigue lifetime of mechanical components?

Friction ◽  
2021 ◽  
Author(s):  
Chia-Jui Hsu ◽  
Andreas Stratmann ◽  
Simon Medina ◽  
Georg Jacobs ◽  
Frank Mücklich ◽  
...  
Keyword(s):  
Boundary Lubrication ◽  
Surface Texturing ◽  
Contact Stresses ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Wear Loss ◽  
Textured Surface ◽  
Periodic Patterns ◽  
Rolling Bearings ◽  
Fatigue Lifetime

AbstractLaser surface texturing (LST) has been proven to improve the tribological performance of machine elements. The micro-scale patterns manufactured by LST may act as lubricant reservoirs, thus supplying oil when encountering insufficient lubrication. However, not many studies have investigated the use of LST in the boundary lubrication regime, likely due to concerns of higher contact stresses that can occur with the increasing surface roughness. This study aims to examine the influence of LST on the fatigue lifetime of thrust rolling bearings under boundary lubrication. A series of periodic patterns were produced on the thrust rolling bearings, using two geometrically different designs, namely cross and dimple patterns. Base oil ISO VG 100 mixed with 0.05 wt% P of zinc dialkyldithiophosphate (ZDDP) was supplied. The bearings with cross patterns reduce the wear loss by two orders of magnitude. The patterns not only retain lubricant in the textured pockets but also enhance the formation of an anti-wear tribofilm. The tribofilm generation may be improved by the higher contact stresses that occur when using the textured surface. Therefore, in contrast to the negative concerns, the ball bearings with cross patterns were instead found to increase the fatigue life by a factor of three.

Tribological effects of laser surface texturing and residual stress

2018 ◽  
Vol 70 (1) ◽  
pp. 126-132 ◽  
Author(s):  
Shuwen Wang ◽  
Feiyan Yan ◽  
Ao Chen
Keyword(s):  
Residual Stress ◽  
Wear Resistance ◽  
Friction And Wear ◽  
Surface Texturing ◽  
Laser Surface ◽  
Friction Reduction ◽  
Laser Surface Texturing ◽  
Wear Testing ◽  
Content Type ◽  
Surface Textures

Purpose The purpose of this paper is to investigate the tribological effects of laser surface texturing (LST) and residual stress on functional surfaces. Design/methodology/approach Three different surface textures (circular dimple, elliptical dimple and groove) with two different textured area ratios (10 and 20 per cent) are designed and fabricated by a Picosecond Nd YAG Laser machine. The friction and wear performance of textured specimens is tested using a UMT-2 friction and wear testing machine in mixed lubrication. Findings Test results show that elliptical dimples exhibit the best performance in wear resistance, circular dimples in friction reduction and grooves in stabilization of friction. The surfaces with larger textured area density exhibit better performance in both friction reduction and wear resistance. The improved performance of LST is the coupled effect of surface texture and residual stress. Originality/value The findings of this study may provide guidance for optimal design of functional surface textures in reciprocating sliding contacts under mixed or hydrodynamic lubrication, which can be used in automotive and other industrial applications.

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